Digital interfaces for computers for audio recording; amplifiers; amplifiers for musical instruments, namely, keyboards; signal converters; audio apparatus, namely, sound equalizers and sound crossovers; stereo receivers; transceivers; microphones; electronic effect pedals for use with sound amplifiers; electric sound mixing apparatus, namely, mixing consoles; computer software for audio editing, recording and production; audio cables; recording media for audio signals, namely, blank digital storage media for recording audio signals; headphones and headphone amplifiers; audio speakers; computer monitors for audio studio use; microphones and amplifiers for use with guitars; electronic sound pickup for guitars; downloadable electronic publications in the nature of manuals in the field of sound recording production; downloadable electronic publications, namely, magazines in the field of audio production; digital music downloadable from the Internet; guitar computer interfaces; interfaces for guitars for use with personal computers, tablet computers, mobile phones and electronic mobile devices, namely, smartphones; guitar amplifiers; downloadable software in the nature of a mobile application for the control and operation of audio equipment